To do the texture:
1. Tape off the area you want to texture
2. Spread a fairly thin layer of epoxy evenly over the area (I used Devcon)
3. Let it setup for a little while until it starts to get tacky. I think I waited about 40 minutes or so.
4. Take a popsicle stick or something similar and bounce it off of the compound. This will pull it up where the stick hits.
5. Once you get it roughed up the way you want it remove the tape and let it finish drying.
6. Once dry file the sharp tips created with the stick

If you google stock texturing there is a how to with pictures that i followed the first time I did it.

So the DE brake comes with specific instructions NOT to turn the brake diameter down any more than it already is. I assume this is because the material on top/bottom of the ports would become too thin. So a slight taper was used to meet the contour of the barrel.